That circuit has only one node and that node is junction on top of R1. The node voltage is measured from that point with respect to ground. There are three currents involved in your circuit as far as that node is concerned: One incoming current to the node and two outgoing current from the node. The incoming current is the total current from the voltage source and the two outgoing currents are the current throug R1 and the other is the current flowing through the inductor. The node current is I1 = I2 + I3. You can now solve the values of the currents using that equation.